Sec Form 4 Filing - KIM SUSAN Y @ AMKOR TECHNOLOGY, INC. - 2023-05-16

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person KIM SUSAN Y 2. Issuer Name and Ticker or Trading Symbol AMKOR TECHNOLOGY, INC. [ AMKR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director X __ 10% Owner _____ Officer (give title below) X __ Other (specify below) Member of 10% owner group (7) (Last) (First) (Middle) C/O SIANA CARR O'CONNOR & LYNAM,, 1500 EAST LANCASTER AVENUE, 3. Date of Earliest Transaction (MM/DD/YY) 05/16/2023 (Street) PAOLI, PA19301-9713 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 05/16/2023 M 8,809 ( 1 ) A $ 0 ( 1 ) 6,982,423 ( 1 ) D Common Stock 1,867,747 ( 2 ) ( 3 ) ( 4 ) I By James J. Kim 2021 GRAT dtd. 12/15/21 Common Stock 2,660,840 ( 2 ) ( 3 ) ( 4 ) I By Agnes C. Kim 2020-1 GRAT dtd. 12/16/20 Common Stock 753,232 ( 2 ) ( 3 ) ( 4 ) I By John T. Kim 2018 GRAT dtd. 2/6/18 Common Stock 1,117,623 ( 2 ) ( 3 ) ( 4 ) I By James J. Kim 2020-1 GRAT dtd. 4/1/20 Common Stock 7,261,498 ( 2 ) ( 3 ) ( 4 ) I By trusts (excl. GRATs) Common Stock 3,678,298 ( 2 ) ( 3 ) ( 4 ) I By own GRATs Common Stock 19,484,809 ( 2 ) ( 3 ) ( 4 ) I By Sujochil, LP Common Stock 2,478,325 ( 2 ) ( 3 ) ( 4 ) ( 5 ) I By Sujoda Investments, LP Common Stock 8,200,000 ( 2 ) ( 3 ) ( 4 ) I By LLCs treated as corporations Common Stock 3,278,001 ( 2 ) ( 3 ) ( 4 ) I By Agnes C. Kim 2023 GRAT dtd. 4/26/23 Common Stock 5,117,004 ( 2 ) ( 3 ) ( 4 ) I By James J. Kim 2023 GRAT dtd. 4/26/23

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Restricted Stock Units ( 1 ) 05/16/2023 M 8,809.4075 ( 1 ) ( 1 ) ( 1 ) Common Stock 8,809.4075 ( 1 ) $ 0 0 D Restricted Stock Units ( 6 ) 05/16/2023 A 8,478 ( 6 ) ( 6 ) Common Stock 8,478 $ 0 8,478 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other KIM SUSAN Y C/O SIANA CARR O'CONNOR & LYNAM, 1500 EAST LANCASTER AVENUE, PAOLI, PA19301-9713 X X Member of 10% owner group (7) Signatures Mark N. Rogers, Attorney-in-Fact for Susan Y. Kim 05/18/2023 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On May 17, 2022, the Reporting Person was granted 8,706 time-vested restricted stock units ("RSUs") pursuant to the Amkor Technology, Inc. (the "Issuer") 2021 Equity Incentive Plan, as amended (the "Plan"), and the applicable award agreement (the "2022 RSUs"). In connection with the vesting of the 2022 RSUs on May 16, 2023: (i) 0.4075 of the 2022 RSUs, which had accrued as dividend equivalent units ("DEUs") with each DEU representing an a dditional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued, were settled in cash; and (ii) the remainder of the 2022 RSUs, including 103 DEUs, converted into common stock of the Issuer on a one-for-one basis. ( 2 )The Reporting Person disclaims beneficial ownership of these securities, except to the extent of the Reporting Person's pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such securities, except to the extent of the Reporting Person's pecuniary interest therein, for purposes of Section 16 of the Securities Exchange Act of 1934, as amended ("Section 16"), or for any other purpose. ( 3 )The Reporting Person is (i) a trustee of trusts for the benefit of her immediate family members (other than grantor retained annuity trusts ("GRATs")) which own 7,261,498 shares of the Issuer's common stock, (ii) a trustee of GRATs for the benefit of members of her immediate family which own 14,794,447 shares of the Issuer's common stock, (iii) a trustee of GRATs of which the Reporting Person was the settlor and is the sole annuitant which own 3,678,298 shares of the Issuer's common stock, (iv) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's common stock, ( 4 )(Continued from Footnote 3) (v) a manager of limited liability companies being treated as corporations for purposes of Section 16, which own 8,200,000 shares of the Issuer's common stock and (vi) as referenced in Footnote 5, a member of Sujoda Management, LLC, which indirectly owns 2,478,325 shares of the Issuer's common stock. Pursuant to Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares. ( 5 )The sole general partner of Sujoda Investments, LP is Sujoda Management, LLC. The Reporting Person is one of three members of Sujoda Management, LLC. Sujoda Management, LLC is being treated as a limited partnership for purposes of Section 16, and, pursuant to the Form 4 instructions, the Reporting Person has elected to treat all of the shares of the Issuer's common stock owned by Sujoda Investments, LP as beneficially owned by the Reporting Person. ( 6 )Represents shares of common stock underlying RSUs granted on May 16, 2023 (the "Grant Date") pursuant to the Plan (the "2023 RSUs"). Subject to the terms and conditions of the applicable award agreement, the 2023 RSUs may be converted into common stock of the Issuer on a one-for-one basis and will vest in full on the earlier of the first anniversary of the Grant Date or the date of the Issuer's first annual meeting of stockholders immediately following the Grant Date. The 2023 RSUs were awarded for no consideration other than the Reporting Person's service as a director of the Issuer.

Remarks: Remarks:(7) The Reporting Person states that the filing of this Form 4 shall not be deemed an admission that the Reporting Person is the beneficial owner of the reported securities owned by the other members of the group, for the purpose of Section 16, or for any other purpose.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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